What kind of atheros card? I have the AR5001X+ (branded as IBM a/b/g in a T42) and it seems stronger than the Intel 2200 b/g in my other T42. I'm curious to know what results you find with the drivers referred to!

ar5006x. What i mean is the Signal Quality not Signal Strength. Me and my colleague were using wireless card last night. I checked the report by tomato, the Signal Quality of my card is always poorer than hers and there were a lot of CRC error which was reported by my atheros card driver.
No difference, because i am already using that driver.